Valve-operating mechanism



Aug. 12, 1924. ,7 1,504,774

v c. Hi MARTIN VALVE OPERATING MEUIIAIII SM Filed July 17. 1923 INVENTORPatented Aug. 12, 1924;

UNITED STATES PATENT OFFICE.

CLYDE H. MARTIN, F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO DURANT MOTOR-SINCORPORATED, A CORPORATION OF DELAWARE.

VALVE-OPERATING MECHANISM.

Application filed July 17,1923. Serial No. 652,016.

To all whom it may concern:

Be it known that I, CLYDE H. llLfARTIN, a citizen of the United States,and a resident of. Pittsburgh, in the county of Allegheny and State ofPennsylvania, have made a new and useful Invention in Improvements inValve-Operating Mechanism, of which the following is a specification.

The invention relates to mechanism for operating valves, andparticularly to the devices for operating the poppet valves of anexplosion motor. Such mechanism ordinarily operates through a pair ofrods, one the valve stem and the other what is known as a push rod,either with an interposed lever arm, or without such lever arm, and itis the primary object of the invention to provide an improved device ofthis kind, (1) which can be applied to the standard engine constructionof the type specified without difliculty and at a very slight expense,(2) which can be readily adjusted to take up the lost motion in theseries of connections, and thus eliminate the noise incident to. suchlost motion ordinarily present in one or more of the plurality of setsof such mechanism in a multi-cylinder engine, and (3) which, when onceadjusted to take up the lost motion, remains substantially permanentlyin the condition of adjustment, so that the ordinary requirement forfrequent adjustments is avoided. Certain embodiments of the inventionare illustrated in the accompanying drawings wherein:

Figure 1 is a partial vertical .section through a cylinder with theimprovement applied thereto. Fig. 2 is an enlarged dctail sectionthrough the upper end of the push rod. Fig. 3 is a partial verticalsection through a modification.

Referring to Figs. 1 and 2, 1 is the cylinder of a gas engine providedwith a piston 2, 3 is the cylinder head, and a is one of the camscarried by the cam shaft for operating the-valve, the showing of theseparts being conventional and constituting no part of my invention whichrelates particularly to the means for operatingthe valve from the cam. I

j The valve 5 1s Of thepoppet type, having a stem 6 guided in thebearing 7 in the cyllnder head, and normally held closed by the spring 8bearing. against the collar 9, a cotter pin 10 serving to hold thecollar in position.

Mounted on the cylinder head upon the shaft 11 is pivoted the'lever 13which at one end bears against the upper end of the valve stem 6. Theother end 14 of the lever is formed into the usual plate, whose lowersurface 15 is flat and plain as indicated in the drawing, or slightlycurved, the term substantially flat being intended to cover bothconditions.

. Between the end 14 of the lever and the cam 4; 18 the push rod,comprising a lower part 16, slidably guided in the cylinder cast mg, andan upper part in the form of the rod 17, guided in the cylinder head at18, the lower end of the rod fitting in a socket in the part 16 andbeing free to turn therethe nut lock 20. The upper end of the adjustingmember is provided with a ball socket which carries the hardened steelball 21. The ball is preferably held against accidental removal from itssocket by peening or bending over the side walls of the socket asindicated at 22. This ball bears against the lower flat or curvedsurface 15 at the end of the lever. V

In operation, to adjust the device, the nut lock 20 is loosened and theadjusting member 19 turned to take up the lost motion and bring theballinto contact with the surface 15, after which the nut lockistightened. hen once adjusted there is practically no wear at the'ballcontact, as the ball is free to turn, and the turning of the ball or therod 17 does not tend to introduce lost motion, as is the case where theordinaryv contactinvolving the engagement of the end of a rod with thelever is .employed. In the latter construction, there is apt to be ahigh spot on theend of the rod,

1 so that when it is turned, in the course of negligible 0a.

is caused, or the valve does not close tightly,

there is a relative sliding movement between the contact surfaceofthe'leve'r and the end of the rod. My construction avoids all of thesedifficulties, as there i sno change in elevation of the ball contactsurface due to the rotation of the rod or ball, and the wear isdistributed over the" ball and its socket to" avoid producing. lostmotion. In practice, the device maybe used indefinitely Withoutadjustment Another advantage of the construction is" incident a; as:applicability" to standard engine; construction ata All of the parts ofthe construction shown in both embodiments ofthe invention, arestandard; except the adjusting" member, so all that is necessary to"apply the device is; to thread thepush rod, and screwon the lock nut andadjusting member. The device can, therefore, be readily applied toexisting engine structures at slight expense, since no machining of thelever end, or other part cooperating with the ball, is required, such asis the case Where a ball is applied between opposing sockets.

Other advantages .of the construction will be apparent to those skilledin the art'.

Fig. 3 illustrates a modification in which thelever 18 of Fig. 1 isomitted, the push rod being placed in line with the stem 23 of the valve24 and. acting directly to open it. In this construction, 25 is thecylinder, 26, the piston,'27 the cylinder head', and 28 the operating(5am, The push rod 29 is guided in the bearing 30,,andi's provided witha screw threaded socket 31 into which is" threaded the adjusting member,comprising a stem 32 and a head 33, the letterheingprovided with asocket carrying the ball 34. After the adjusting member is screwed bythe ant-100k 37. The valve is normally closed by thespring35,-bearingagainst the collar 36 secured to the stem of the valve.

Vvhalt I claim is:

1,111 combination in an engine structure provided with" an operating camand a valve, having a stem, normally held closed by means of spring, ofoperating means for the stern comprising a lever fulcrurned intermediateits ends andengaging. the stem at one end and having: at its other end asubstantially flat surface, av push rod operated' swaths cam at one end,means for guiding said push rod in sliding. movement parallel to-t he ofthe enginecylinder, an adjusting member screw threaded on the other endof the push rod and provided with a ball socket, a ball in said socket,free to termediate itsends and engaging the stem atone end and having atits other end a substantially flat surface, a push rod operated from thecam at one end, means for guiding ada ter rod insliding movementparallel to the azris of the engine cylinder, an adjusting; member screwthreaded on the other end of the push rod and provided with a ballsocket, a ball in said socket free to rotate, but held against lateralmovement by the walls of the socket and engaging said fiat surface onsaid lever, and, a nut lock for said adjusting member, also threaded onsaid push rod, the side edges of the adjusting member'being peened orbent over to hold said ball in place in said socket. v

3. In conibin'ationin an engine structure provided with an operating camand a valve, having a stem, normally held closed by means-of a spring,of operating means for the stem comprising a lever fulcrumedintermediateits ends and engagingthe stem at one end and having at itsother end a substantially flat surface, a push rodoperated from the camand comprising an inner member, means for guiding said push rod insliding movement parallel to the axis of the engine cylinder engagingthe cam at one end and having a socket at its other end, and an outermember fitting at one end in said socket free to turn therein, anadjusting member threaded on the other end of said outer member andprovided with a ball socket, a ball in said socket free to rotate, butheld against lateral movement by the walls of the socket and engagingsaid flat surface on said lever, and a nut lock for said adjustingmember, also threaded on 7 said outer member.

in sliding movement parallel to the axis of the engine cylinder engagingthe cam at one end and having a socket at its other end, and an outermember fitting at one end in said socket free to turn therein, anadjusting member threaded on the other end of said outer member andprovided with a ball socket, a ball in said socket free to rotate, butheld against lateral movement by the Walls of the socket and engagingsaid flat surface on said lever, and a nut lock for said adjustingmember, also threaded on to hold said ball in place in said socket.

In testimony whereof, I have hereunto subscribed my 1923.

name this 19th day of June,

CLYDE H. MARTIN.

